This invention relates to collet chucks--toolholders and workholders having collets--and more particularly to collet chucks of the type including a plurality of substantially rigid gripper members in an annular array, the gripper members being angularly or circumferentially spaced apart in said array by resilient members or resilient means. The present invention is widely applicable to toolholders and workholders which grasp any round or faceted tool shank or workpiece, for example, drill bits, end mills, reamers, and taps.
It would frequently be advantageous to be able to adjust the location of the center of a toolholder or workholder transverse to the axis with which the collet is nominally concentric. Such adjustment would make it possible to compensate for runout--a lack of concentricity of the tool or object within the toolholder or workholder, caused by minor imperfections in the collet and/or in the object being gripped by the collet.
It is therefore an object of this invention to provide improved toolholders and workholders having collets which minimize runout where high accuracy is required.
It is a more particular object of this invention to provide toolholders and workholders having collets in which the center of the toolholder or workholder can be shifted transverse to the axis with which the collet is nominally concentric without a need for repetitive chucking and unchucking of the object or tool to attain the required adjustment.